The present invention relates to a top stack linkage for a convertible top.
Convertible tops are supported by and moved by a top stack linkage. The top stack linkage includes a plurality of bows that are joined on opposite lateral sides by a linkage that is extended in its full up position and folded back onto itself in the full down position.
Prior art top stack linkages include a rear rail assembly that is connected to a scissor link mechanism that spans the second bow and interconnects a center rail to a front rail above the second bow. The scissor link mechanism causes the front rail to pivot over the center rail. The scissor link is pulled by a pulling link connected between a point on the scissor link located above the center rail and the rear rail assembly. In prior art top stack arrangements, the pivot on the rear rail assembly is the highest point over which the front rail and number one bow are folded. This arrangement increases the height of the top stack in its retracted position and also increases the height of the roof in the extended position of the convertible top.
Styling and space requirements are adversely impacted by the vertical spacing required to accommodate the pull link.
These and other problems associated with prior art top stack linkages are addressed by the present invention as summarized below.
According to the present invention, a compact, low profile top stack for a convertible top is provided. A lower profile is possible in accordance with the invention in both the full up and full down positions of the convertible top.
According to the present invention, a push link is connected to the rear rail assembly and to a lower extension of a scissor link that bridges the center rail and front rail at the number two bow. As the convertible top moves from its extended position toward its retracted position, the push link is pushed by the rear rail assembly to cause the scissor link extension to move forward. The forward movement of the scissor link extension causes the scissor link to lift the number one bow and the front rail and move rearwardly over the center rail. The lower scissor link extension and reduced height of the rear rail assembly results in a lower profile for the convertible top in both the full up position and in the full down position.
An aspect of the invention provides a left and right linkage for extending and retracting the convertible top. Each linkage includes a rear four bar linkage interconnected to the vehicle and a forward four bar linkage supporting the front rail. The front rail is adapted to be secured to the windshield of the vehicle. A push link connects the front and rear linkages for simultaneous motion, causing the forward linkage to invert the front rail as the rear linkage contracts, thus retracting the convertible top.
Another aspect of the invention is to provide compact linkages wherein the push link shifts forward, with respect to the center rail, pushing the forward linkage and inverting the front rail as the convertible top retracts. The push link, in turn, shifts towards the rear when the convertible top is extending.
Under the invention, a pushing four bar linkage interconnects the rear and forward linkages. The pushing linkage can take the shape of a parallelogram. The push link and portions of links of both the rear and forward linkages define the pushing linkage.
These and other advantages and objects of the invention will be better understood in view of the attached drawings and following detailed description of the invention.